uacasszx

let objects = [{a: true, b: 'string1'}, {a: false, b: 'string2'}, {a: false, b: 'string3'}, {a: true, b: 'string4'}, {a: false, b: 'string5'}];
objects.filter(object => (object.a === true && object.b.indexOf('string') !== -1));